Interaction of a CO molecule with a Pt monatomic wire: Electronic structure and ballistic conductance

Abstract

We carry out a first-principles density functional study of the interaction between a monatomic Pt wire and a CO molecule, comparing the energy of different adsorption configurations (bridge, on top, substitutional, and tilted bridge) and discussing the effects of spin-orbit (SO) coupling on the electronic structure and on the ballistic conductance of two of these systems (bridge and substitutional). We find that, when the wire is unstrained, the bridge configuration is energetically favored, while the substitutional geometry becomes possible only after the breaking of the Pt-Pt bond next to CO. The interaction can be described by a donation/back-donation process similar to that occurring when CO adsorbs on transition-metal surfaces, a picture which remains valid also in presence of SO coupling. The ballistic conductance of the (tipless) nanowire is not much reduced by the adsorption of the molecule on the bridge and on-top sites, but shows a significant drop in the substitutional case. The differences in the electronic structure due to the SO coupling influence the transmission only at energies far away from the Fermi level so that fully-and scalar-relativistic conductances do not differ significantly.

Probing the Orbital Origin of Conductance Oscillations in Atomic Chains

“…Yet, while theoretical calculations can estimate the different conduction channels and their relation to the orbital structure [11][12][13][14][15][16] , experiments are mostly limited to measuring the overall conductance.…”

Understanding formation mechanism of ZnO diatomic chain and multi-shell structure using physical mechanics: Molecular dynamics and first-principle simulations?

“…The MC has been found in many materials; however, most materials are noble metal [4,19,22]. In this paper, we present our calculation results about the formation of the diatomic chain (DC) for ZnO NW, which is a semiconducting material and attracted many focus of research.…”

An initio study of Pt induced nanowires on Ge(001)

“…Another interesting geometrical feature is that in most cases the adsorbed CO molecule is tilted with regard to the surface, unlike the behavior of CO molecules on clean Pt surfaces. In case of CO adsorbed on top of Pt atoms, the C-Pt bond length is just slightly longer than what is found for CO on Pt (111) in an ontop configuration. [100,114] The adsorption energies given in Table 5.1 show a very clear preference for CO adsorption on Pt (sites A1-A4).…”

“…[31,32] Calculations on the interaction of CO with a free standing Pt monatomic wire suggest a similar behavior. [111] However, in Chapter 4 we showed the NWs to be modeled by Pt induced Ge NWs. In this model the NWs consist of Ge dimers placed in the Pt lined troughs of a Pt modified Ge(001) reconstructed surface.…”

“…In their theoretical study, Sclauzero et al [111] found that for an intermediate inter-platinumdistance of 3.7-5.3Å a configuration with the CO molecule bridging the gap between two Pt atoms is the most stable configuration, while for an inter-platinum-distance around 2.50Å the bridge configuration, with the C atom bound to two Pt atoms, was found to be most favorable. In the A3b-situation three Pt atoms are involved.…”